WordSmith:

Check for words that are used well, overused, incorrectly used, or could be substituted for more descriptive or interesting words.

Punctuation Person:
Check grammar and punctuation. Look for fragments and run-on sentences.

Reality Checker: 
Check facts and perform a plagiarism check by popping snippets of the writing into a Google Search.

Big Picture Person: 
Check to make sure the writing is complete. Focus on main ideas, paragraphs, details and use of transitions.

Tense Tracker:

Check to make sure the tense remains constant. It's easier to write in the past tense than it is to write in the present.

Your Own:

Design and redesign roles based on the skills you are covering in your writing curriculum.